This rapid expansion and contraction creates the sound wave that we hear as thunder. Although a lightning discharge usually strikes just one spot on the ground, it travels many miles through the air. ... The loud boom that you sometimes hear is created by the main lightning channel as it reaches the ground.

What does a lightning strike sound like?

The air around the lightning bolt expands faster than the speed of sound, which creates a shock wave of thunder. When you're this close to the bolt, though, it sounds more like a bullet from a gun. Alderete's video shakes during the strike, but you can still see beads of plasma along the channel as the light fades.

Why does lightning have no sound?

If you see lightning but don't hear thunder, it is because the thunder is too far away. ... What we see as a lightning strike actually comes from the ground up, according to NOAA. Typically, a cloud-to-ground flash lowers a path of (invisible) negative electricity towards the ground.